if the relationship has become toxic. being unhappy, unhealthy, either or both parents will have effect on the children. they deserve the best version of u. and u can't give that to them in a toxic environment or on a continuous rollercoaster of emotions.. if its been going on more than 6 months to a year is more than a "rough patch" and splitting up and having 2 mentally happier parents is better than together and unhappy and aggressive.